Apache Geronimo supports Hot Deployment. You can copy an application JAR file into the <geronimo_home>/deploy directory and the application will be deployed automatically. This will also work for uninstalling or refreshing applications previously deployed via this method. Alternatively, you may also copy the directory (unpacked) for the application module instead of copying a single JAR file.
Note that with this deployment method you have to include the deployment plan in the package, this method does not support external plans. Also note that applications deployed via the Deployer tool will not be listed in the <geronimo_home>/deploy directory.